Reduced iron and cobalt levels in response to curcumin supplementation are not responsible for the prolonged larval development and do not affect the oxidative stress tolerance and polyamine status of D. melanogaster.

Recent reports indicated that the phytochemical curcumin possesses iron-chelating activity. Here, by employing the fruit fly Drosophila melanogaster, we conducted feeding studies supplementing curcumin or, as a control, the iron chelator bathophenanthroline (BPA). First, the absorption and further metabolization of dietary curcuminoids were proved by metabolomics analyses. Next, we found that 0.2% dietary curcumin, similar to BPA, lowered the iron but also the cobalt content, and to a lesser extent affected the manganese and zinc status. Supplementation during larval stages was required and sufficient for both compounds to elicit these alterations in adult animals. However, curcumin-induced retarded larval development was not attributable to the changed trace metal status. In addition, a reduction in the iron content of up to 70% by curcumin or BPA supplementation did not reduce heme-dependent catalase activity and tolerance toward H2 O2 in D. melanogaster. Moreover, polyamines were not influenced by curcumin treatment and decreased iron levels. This was confirmed for selected organs from 0.2% curcumin-treated mice, except for the spleen. Here, elevated spermidine level and concomitant upregulation of genes involved in polyamine production were associated with a putatively anemia-derived increased spleen mass. Our data underline that the metal-chelating property of curcumin needs to be considered in feeding studies.

Unraveling the effects of low protein-phenol binding affinity on the structural properties of beta-lactoglobulin.

Non-covalent interactions of phenolics with proteins cannot always be readily identified, often leading to contradictory results described in the literature. This results in uncertainties as to what extent phenolics can be added to protein solutions (for example for bioactivity studies) without affecting the protein structure. Here, we clarify which tea phenolics (epigallocatechin gallate (EGCG), epicatechin and gallic acid) interact with the whey protein ß-lactoglobulin by combining various state-of-the-art-methods. STD-NMR revealed that all rings of EGCG can interact with native ß-lactoglobulin, indicating multidentate binding, as confirmed by the small angle X-ray scattering experiments. For epicatechin, unspecific interactions were found only at higher protein:epicatechin molar ratios and only with 1H NMR shift perturbation and FTIR. For gallic acid, none of the methods found evidence for an interaction with ß-lactoglobulin. Thus, gallic acid and epicatechin can be added to native BLG, for example as antioxidants without causing modification within wide concentration ranges.

Vitamin C and Omega-3 Fatty Acid Intake Is Associated with Human Periodontitis-A Nested Case-Control Study.

Vitamins and omega-3 fatty acids (Ω3FA) modulate periodontitis-associated inflammatory processes. The aim of the current investigation was to evaluate associations of oral nutrient intake and corresponding serum metabolites with clinical severity of human periodontitis. Within the Food Chain Plus cohort, 373 periodontitis patients­245 without (POL) and 128 with tooth loss (PWL)­were matched to 373 controls based on sex, smoking habit, age and body mass index in a nested case-control design. The amount of oral intake of vitamins and Ω3FAs was assessed from nutritional data using a Food Frequency Questionnaire. Oral intake and circulatory bioavailability of vitamins and Ω3FA serum metabolomics were compared, using ultra-high-resolution mass spectrometry. Periodontitis patients exhibited a significantly higher oral intake of vitamin C and Ω3FA Docosapentaenoic acid (p < 0.05) compared to controls. Nutritional intake of vitamin C was higher in PWL, while the intake of Docosapentaenoic acid was increased in POL (p < 0.05) compared to controls. In accordance, serum levels of Docosapentaenoic acid were also increased in POL (p < 0.01) compared to controls. Vitamin C and the Ω3FA Docosapentaenoic acid might play a role in the pathophysiology of human periodontitis. Further studies on individualized nutritional intake and periodontitis progression and therapy are necessary.

Precision Nutrition in Chronic Inflammation.

The molecular foundation of chronic inflammatory diseases (CIDs) can differ markedly between individuals. As our understanding of the biochemical mechanisms underlying individual disease manifestations and progressions expands, new strategies to adjust treatments to the patient's characteristics will continue to profoundly transform clinical practice. Nutrition has long been recognized as an important determinant of inflammatory disease phenotypes and treatment response. Yet empirical work demonstrating the therapeutic effectiveness of patient-tailored nutrition remains scarce. This is mainly due to the challenges presented by long-term effects of nutrition, variations in inter-individual gastrointestinal microbiota, the multiplicity of human metabolic pathways potentially affected by food ingredients, nutrition behavior, and the complexity of food composition. Historically, these challenges have been addressed in both human studies and experimental model laboratory studies primarily by using individual nutrition data collection in tandem with large-scale biomolecular data acquisition (e.g. genomics, metabolomics, etc.). This review highlights recent findings in the field of precision nutrition and their potential implications for the development of personalized treatment strategies for CIDs. It emphasizes the importance of computational approaches to integrate nutritional information into multi-omics data analysis and to predict which molecular mechanisms may explain how nutrients intersect with disease pathways. We conclude that recent findings point towards the unexhausted potential of nutrition as part of personalized medicine in chronic inflammation.

Encapsulation of anthocyanins from bilberries - Effects on bioavailability and intestinal accessibility in humans.

Anthocyanins are flavonoids that have been suggested to provide beneficial health effects. The biological activity of anthocyanins is influenced by their pharmacokinetic properties, but anthocyanins are associated with limited bioavailability in humans. In the presented study, we investigated how the encapsulation of bilberry extract (BE), a source of anthocyanins, with either whey protein or citrus pectin influences the bioavailability and intestinal accessibility of anthocyanins in humans. We performed an intervention study that analyzed anthocyanins and their degradation products in the urine, plasma, and ileal effluent of healthy volunteers and ileostomists (subjects without an intact colon). We were able to show, that whey protein encapsulation modulated short-term bioavailability and that citrus pectin encapsulation increased intestinal accessibility during passage through the small intestine and modulated the formation of the degradation product phloroglucinol aldehyde (PGAL) in human plasma.

Whey Protein Complexes with Green Tea Polyphenols: Antimicrobial, Osteoblast-Stimulatory, and Antioxidant Activities.

Polyphenols are known for their antimicrobial activity, whilst both polyphenols and the globular protein ß-lactoglobulin (bLG) are suggested to have antioxidant properties and promote cell proliferation. These are potentially useful properties for a tissue-engineered construct, though it is unknown if they are retained when both compounds are used in combination. In this study, a range of different microbes and an osteoblast-like cell line (human fetal osteoblast, hFOB) were used to assess the combined effect of: (1) green tea extract (GTE), rich in the polyphenol epigallocatechin gallate (EGCG), and (2) whey protein isolate (WPI), rich in bLG. It was shown that approximately 20-48% of the EGCG in GTE reacted with WPI. GTE inhibited the growth of Gram-positive bacteria, an effect which was potentiated by the addition of WPI. GTE alone also significantly inhibited the growth of hFOB cells after 1, 4, and 7 days of culture. Alternatively, WPI significantly promoted hFOB cell growth in the absence of GTE and attenuated the effect of GTE at low concentrations (64 µg/mL) after 4 and 7 days. Low concentrations of WPI (50 µg/mL) also promoted the expression of the early osteogenic marker alkaline phosphatase (ALP) by hFOB cells, whereas GTE inhibited ALP activity. Therefore, the antioxidant effects of GTE can be boosted by WPI, but GTE is not suitable to be used as part of a tissue-engineered construct due to its cytotoxic effects which negate any positive effect WPI has on cell proliferation.

Antimicrobial effect of emulsion-encapsulated isoeugenol against biofilms of food pathogens and spoilage bacteria.

Food-related biofilms can cause food-borne illnesses and spoilage, both of which are problems on a global level. Essential oils are compounds derived from plant material that have a potential to be used in natural food preservation in the future since they are natural antimicrobials. Bacterial biofilms are particularly resilient towards biocides, and preservatives that effectively eradicate biofilms are therefore needed. In this study, we test the antibacterial properties of emulsion-encapsulated and unencapsulated isoeugenol against biofilms of Lis. monocytogenes, S. aureus, P. fluorescens and Leu. mesenteroides in tryptic soy broth and carrot juice. We show that emulsion encapsulation enhances the antimicrobial properties of isoeugenol against biofilms in media but not in carrot juice. Some of the isoeugenol emulsions were coated with chitosan, and treatment of biofilms with these emulsions disrupted the biofilm structure. Furthermore, we show that addition of the surfactant Tween 80, which is commonly used to disperse oils in food, hampers the antibacterial properties of isoeugenol. This finding highlights that common food additives, such as surfactants, may have an adverse effect on the antibacterial activity of preservatives. Isoeugenol is a promising candidate as a future food preservative because it works almost equally well against planktonic bacteria and biofilms. Emulsion encapsulation has potential benefits for the efficacy of isoeugenol, but the effect of encapsulation depends on the properties of food matrix in which isoeugenol is to be applied.

ß-Lactoglobulin as nanotransporter for allicin: Sensory properties and applicability in food.

The thiosulfinate allicin is a labile, bioactive compound of garlic. In order to enrich allicin in a functional food, a delivery system which stabilises the compound and masks its intense flavour is necessary. In the present study allicin was covalently bound to the whey protein ß-lactoglobulin and the incorporation of this transporter in a food matrix was tested. The sensory properties of the pure functional ingredient as well as of an enriched beverage were characterised by quantitative descriptive analysis. The concentration of volatile compounds was analysed by headspace gas chromatography-mass spectrometry. The garlic-related organoleptic properties of garlic powder were significantly improved by the binding of allicin in combination with spray drying. After purification of the modified ß-lactoglobulin the garlic taste and smell were barely perceptible. ß-Lactoglobulin modified with allicin provided a stable functional ingredient that can be used to enrich a broad range of food products.

ß-Lactoglobulin as nanotransporter--Part I: Binding of organosulfur compounds.

The binding reaction of allicin and diallyl disulfide with ß-lactoglobulin and the influence of pH value and protein denaturation on this reaction have been examined in the present study. Regardless of the structural similarity of both the organosulfur compounds, their binding behavior was significantly different. Both ligands were covalently bound by the free thiol group of the protein, whereas the affinity for allicin was significantly higher. In addition, diallyl disulfide was non-covalently bound. The binding reaction of both ligands was very sensitive to the pH value during incubation. The optimal pH range was between pH 8.0 and 9.0. Protein denaturation increased the reaction rate and reduced the number of binding sites for allicin, whereas the number of non-covalent binding sites increased for diallyl disulfide. Based on these findings, it can be proposed that the covalent modification of ß-lactoglobulin functions as a specific transporter stabilizing allicin or diallyl disulfide.

ß-Lactoglobulin as nanotransporter--Part II: Characterization of the covalent protein modification by allicin and diallyl disulfide.

The whey protein ß-lactoglobulin has been proposed as a transporter for covalent bound bioactive compounds in order to enhance their stability and reduce their sensory perception. The garlic derived compounds allicin and diallyl disulfide were bound covalently to the native and heat denatured protein. The binding site and the influence of the modification on the digestibility were determined by mass spectrometric analysis of the modified ß-lactoglobulin. Further, the conformation of the modified protein was assessed by circular dichroism and dynamic light scattering. The free thiol group of Cys(121) turned out to be the major binding site. After proteolysis with trypsin at pH 7 but not with pepsin at pH 2, a limited transfer to other cysteinyl residues was observed. The covalently bound ligands did not mask any proteolytic cleavage sites of pepsin, trypsin or chymotrypsin. The modified ß-lactoglobulin showed a native like conformation, besides a moderate loosening of protein folding. The covalent binding of organosulfur compounds to ß-lactoglobulin provides a bioactive ingredient without impairing the digestibility and functional properties of the protein.

Is the antioxidative effectiveness of a bilberry extract influenced by encapsulation?

BACKGROUND: Bilberries (Vaccinium myrtillus L.) have been suggested to have preventive properties against diseases associated with oxidative stress such as colon cancer or inflammatory bowel diseases. Therefore the gastrointestinal tract is regarded as a potential target for prevention. In this study the antioxidative properties of a commercially available anthocyanin-rich bilberry extract (BE) were investigated in comparison with four different BE-loaded microcapsule systems. As markers to describe the antioxidant status in this cellular system, intracellular reactive oxygen species (ROS) levels, oxidative DNA damage and total glutathione (tGSH) levels were monitored. RESULTS: Incubations with the BE-loaded capsule systems showed an increase in cellular glutathione levels and reduction of ROS levels at high BE concentrations (100-500 µg mL(-1) ) and a positive effect on the formation of DNA strand breaks (5-10 µg mL(-1) BE). The biological properties of BE-loaded pectin amide core-shell capsules, whey protein matrix capsules and coated apple pectin matrix capsules were comparable to those of the non-encapsulated BE. CONCLUSION: Overall, the BE and the encapsulated BE types tested have antioxidative activity under the studied assay conditions in terms of the prevention of oxidative DNA damage, the reduction of intracellular ROS and the enhancement of cellular tGSH.

Preparation and comparative release characteristics of three anthocyanin encapsulation systems.

Bilberries (Vaccinium myrtillus L.) and their major polyphenolic constituents, anthocyanins, have preventive activities inter alia against colon cancer and inflammatory bowel diseases. However, anthocyanins are sensitive to environmental conditions; thus their bioavailability in the gastrointestinal tract is an important determinant of their in vivo activity. In the study reported here, the potential benefits of encapsulating an anthocyanin rich bilberry extract (BE) on anthocyanin stability were investigated. Nonencapsulated BE and three different BE loaded microcapsule systems were incubated in simulated gastric fluid (SGF) and fed state simulated intestinal fluid (FeSSIF). After exposure to these media, released anthocyanins were identified and quantified by HPLC with UV/Vis detection. Although a rapid release of anthocyanins was observed within the first 20 min, encapsulation of anthocyanins doubled the amount of available anthocyanins after 150 min of incubation. These results illustrate the ability of encapsulation to inhibit early degradation of anthocyanins in the intestinal system.

Enriched cereal bars are more effective in increasing plasma quercetin compared with quercetin from powder-filled hard capsules.

The flavonol quercetin, is one of the major flavonoids found in edible plants. The bioavailability of quercetin in humans may be influenced by the food matrix in which it is consumed as well as by its chemical and physical form. The objective of the present study was to investigate the biokinetics of quercetin from quercetin-enriched cereal bars and quercetin powder-filled hard capsules. In a randomised, single-blinded, diet-controlled cross-over study, six healthy women aged 22-28 years took a single oral dose of approximately 130 mg quercetin equivalents from either quercetin-enriched cereal bars (containing 93·3 % quercetin aglycone plus 6·7 % quercetin-4'-glucoside) or quercetin powder-filled hard capsules (100 % quercetin aglycone). Blood samples were drawn before and after quercetin administration over a 24 h period. The concentrations of quercetin and its monomethylated derivatives, isorhamnetin (3'-O-methyl quercetin) and tamarixetin (4'-O-methyl quercetin), were measured by HPLC with fluorescence detection after plasma enzymatic treatment. The systemic availability as determined by comparing the plasma concentration-time curves of quercetin was found to be five times and the cmax values six times higher after ingestion of 130 mg quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In contrast, tmax did not differ significantly between the two treatments. The cmax values for isorhamnetin and tamarixetin were four and nine times higher after ingestion of quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In conclusion, quercetin from quercetin-enriched cereal bars is significantly more bioavailable than from quercetin powder-filled hard capsules.

The more--the better? Estimating the inhibitory activity of alpha-tocopherol towards lipid oxidation.

Tocopherols are considered to be powerful antioxidants, but prooxidative effects are discussed for higher concentrations. The aim of this in vitro study was to investigate the dose-dependent inhibition of oxidation product formation caused by alpha-tocopherol, and to estimate the range of maximum antioxidant activity of alpha-tocopherol at different stages of lipid oxidation. Alpha-tocopherol was added to rapeseed oil triglycerides (ROTG, purified rapeseed oil) in concentrations ranging from 25 to 1500 micromol/kg ROTG. The inhibitory activity of alpha-tocopherol increased up to a concentration of 100 micromol/kg ROTG. A concentration of 125 micromol alpha-tocopherol/ kg ROTG did not result in an improved antioxidant effect. The formation of volatile secondary oxidation products followed the same trend, and the maximum inhibitory effect was also found for 100 micromol alpha-tocopherol/kg. Further, concentrations between 250 and 1500 micromol alpha-tocopherol/kg ROTG clearly caused increased formation of hydroperoxides during the induction period. However, compared to the control, all tested alpha-tocopherol concentrations resulted in a reduction of hydroperoxide formation and no prooxidative effects were observed.